1. Field of the Invention
The present invention relates to a method and device for illumination in a terminated cable part inspection device for a stripped terminal crimping machine which inspects stripped parts and terminal crimped parts of cables on a bidirectional path along which cable ends are transported.
2. Description of the Background Art
Conventional inspection of the stripping conditions of a coating-removed stripped part at a cable end and the crimping conditions of a terminal crimped part formed by crimping a crimp terminal to the stripped part by means of image processing generally involves photographing the stripped part and terminal crimped part by an image pickup means such as a television camera and two-dimensional CCD camera, displaying the image photographed by the image pickup means on a monitoring television receiver, processing the image by an image processing means, judging whether or not the stripping and crimping conditions are defective, and displaying the result of judgement by means of a printer or display unit.
A device for such inspection includes a keyboard for operation which is used to input program data and the like required for image processing.
This type of inspection device is disclosed in, for example, Japanese Patent Application Laid-Open No. 61-133844(1986). In this disclosure, a stripping portion strips the coating of a cable at a cable end held by a cable holding portion of an arm. The arm is pivoted to transport the stripped part of the cable at the cable end to a terminal crimping portion which in turn crimps a crimp terminal to the stripped part. The arm is then pivoted in the opposite direction to transport the terminal crimped part of the cable to the stripping position. The cable is transported by a predetermined length in a predetermined direction and cut in position. Cables are sequentially subjected to the stripping and terminal crimping by the similar procedure.
The inspection device for inspecting the stripping and crimping conditions is provided on a bidirectional path along which the cable is transported between the stripping portion and terminal crimping portion.
The inspection device comprises a light source and a television camera on opposite sides of the bidirectional path, and a sensor including a light projector and a light receiver on opposite sides thereof for detecting a cable photographing timing. The sensor detects the stripped part and terminal crimped part passing therethrough, and the light source emits light in response to the detection output of the sensor. The television camera photographs the silhouette image of the stripped and terminal crimped parts, and an image processor captures and processes the silhouette image. In this manner, whether or not the stripping and crimping conditions are defective is determined.
However, the inspection device disclosed in Japanese Patent Application Laid-Open No. 61-133844 is of the type wherein the silhouette image is captured, that is, only the outline information of the silhouette is captured. The inspection device receives a small amount of image information and is incapable of detecting crimping failures and cores extending off in the silhouette portion, resulting in inaccurate inspection.
Another inspection device is of the type wherein an object to be inspected is illuminated from the photographing direction of the image pickup means to capture a reflected image for receiving more image information. However, this inspection device is designed to photograph the stationary object to be inspected in a predetermined inspection position. Thus, illumination by a lighting fixture is only required to ensure an illuminance needed for photographing in the predetermined inspection position.
However, in the above stated stripped terminal crimping machine, the cable end held by the arm in cantilevered fashion and typically moved along the bidirectional path at high speeds of about 2000 mm/s is photographed. This causes the distal end of the cable moved in a first direction along the bidirectional path to deflect slightly rearwardly in the transport direction. On the other hand, the cable end moved in a second direction opposite from the first direction along the bidirectional path is weighted with the crimp terminal crimped thereto, causing the distal end of the cable to deflect by a greater amount rearwardly in the opposite transport direction. The attitude of the stripped cable end when photographed is greatly deviated along the bidirectional path from the attitude of the terminal-crimped cable end when photographed. The attitude of the cable end when photographed and the location of the cable end when passing along the bidirectional path are deviated depending on the cable diameter and the crimp terminal types. It is hence necessary to ensure a certain range of illuminance required for photographing.